Scold's Bridle Unique Helmet Activating "Worn Sandals" Affliction in Trial of The Sekhemas

As the title states, whenever I cast a spell with the Scold's Bridle unique helmet equipped (Take #% of mana costs you pay for skills as physical damage), it is causing the "Worn Sandals" affliction (30% less movement speed if you've been hit by an enemy recently) to activate, drastically slowing movement speed down. I have tested it several times in and out of combat and it is very consistently happening. With this being self-inflicted damage, this shouldn't be activating the affliction, as the text states that the damage must come from an "enemy".